S100A4 and lobular neoplasia: All urine S100 protein levels had a weak positive association with SLEDAI-R score in patients with active LN (for S100A4, rs = 0.34, p = 0.014; for S100A6, rs = 0.22, p = 0.12; for S100A8/9, rs = 0.31, p = 0.03; for S100A12, rs = 0.4, p = 0.003).